EMERITUS Professor Graham Dixon-Lewis, who has died suddenly aged 88, was a pioneer in the detailed understanding of the nature of flames.
His work at Leeds University has been vital in achieving the efficient combustion of natural gas and other fuels with minimum pollution, a matter of immense world-wide environmental importance.
After a ground-breaking paper on the structure of slow burning hydrogen flames, presented to the Ninth International Symposium on Combustion in 1962 at Cornell University, he became renowned as an international expert and among the word's foremost authorities.
He worked in the field for 60 years, had 94 published papers, and his work has been highly influential, not only in relation to flames, but in the wider field of chemical kinetics and fuel technology.
His work demonstrated both a versatile experimental approach and a profound understanding of the theoretical aspects of the subject.
Professor Dixon-Lewis also exerted considerable influence as a mentor to his research students and co-workers at Leeds University, many of whom have since gone on to occupy prominent positions in the combustion field in all corners of the world.
The elder child of Daniel and Eleanor Dixon-Lewis of Newport, South Wales, Graham was born into a household where there was always a strong encouragement to persevere and do well.
He went to Newport High School for Boys, benefiting, he believed, from an education system which "provided upward mobility for those with capabilities".
In 1940 he won the Welsh Foundation Scholarship to Jesus College, Oxford, where he studied chemistry.
It was during this time that his lifelong interest in combustion and flames was fired by his investigations, as a special reservist (1943-44), into the prevention of muzzle flash from guns which was a danger to soldiers in the field.
He remained at Oxford to undertake research for a DPhil, but before he was awarded it in 1948, he was offered a good position working on polymers for Courtaulds Ltd, based in the company's fundamental research laboratory in Maidenhead.
His interest in combustion proved stronger, however, and he took a less lucrative position as research officer with the Gas Board in Beckenham, and in 1950 his domestic and personal life received a great boost when he married Patricia Best.
The Board was disbanded following nationalisation of the gas industry in 1953, and Graham joined the staff of the Gas Research Council at Leeds University as a Research Chemist in the then Department of Coal Gas and Fuel Industries (which later became the Department of Fuel and Energy).
In 1970 he was made an Honorary Reader in Flame and Combustion Science and in 1977 he joined the university's academic staff, and the following year was given a Personal Chair in recognition of his pioneering work.
His international reputation and versatility brought him opportunities to work abroad and elsewhere in the UK. He enjoyed secondments as Visiting Professor at the John Hopkins University, Maryland, in 1965; some months as a Senior Research Fellow at the University of Cambridge in 1993-4; and two periods of time spent as Visiting Scientist, firstly at Sandia National Laboratories, Livermore, California in 1987, and secondly at the Max-Planck Institute, Gottingen, in 1994.
Following his retirement in 1987, he was made an Emeritus Professor, and his research continued uninterrupted, his scientific achievements being recognised in the form of numerous honours and medals.
In 1995 he was elected as a Fellow of the Royal Society. Further honours included the Sugden Award of the Combustion Institute (British Section) for "the most significant contribution to combustion research in 1997," and last year the Huw Edwards Prize from the Institute of Physics for Services to Combustion Physics.
He presented his last paper, aged 87, in April of this year to the International Sixth Fire and Explosion Hazards Seminar at Leeds.
Graham Dixon-Lewis presented the slightly unexpected persona of a traditional English gentleman with the hint of a Welsh accent. He was universally admired for his warm friendliness, his kindness, his quiet humour and, as an eminent scientist, his generosity and willingness to help anyone who asked for his thoughts.
He is survived by his wife, Patricia, their daughters Stephanie and Melanie, and their son Andrew.